You can choose what a child will look like, etc, but you will never change their personality. So really, the lab process is entirely superficial.

And in that case, go ahead. Choose hair, sex, eye color, etc because you'll never be able to change who that person will become. And, if you have a family of five girls and you want a boy (perhaps to carry on the family name?) go right ahead. I have nothing against the whole "God's will" concept, and I would never personally alter my child's appearance in utero, but whatever floats your boat.

It's just that careful consideration should be taken as to WHY you're changing what you are.